<!doctype html>
<!--
Copyright 2018 The Immersive Web Community Group

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-->
<html>
  <head>
    <meta charset='utf-8'>
    <meta name='viewport' content='width=device-width, initial-scale=1, user-scalable=no'>
    <meta name='mobile-web-app-capable' content='yes'>
    <meta name='apple-mobile-web-app-capable' content='yes'>

    <!-- Origin Trial Token, feature = WebXR Device API (For Chrome M76+), origin = storage.googleapis.com, expires = 2019-07-24 -->
    <meta http-equiv="origin-trial" data-feature="WebXR Device API (For Chrome M76+)" data-expires="2019-07-24" content="Ap6io/uhkGK7vXCD+golNnQfj8wJ4so790EzZoqb8YOljMXIBTvBEQFPTHYIz5d/BgtuwZTKOLrmHAOt30f38g8AAABxeyJvcmlnaW4iOiJodHRwczovL3N0b3JhZ2UuZ29vZ2xlYXBpcy5jb206NDQzIiwiZmVhdHVyZSI6IldlYlhSRGV2aWNlTTc2IiwiZXhwaXJ5IjoxNTY0MDA5MzU2LCJpc1N1YmRvbWFpbiI6dHJ1ZX0=">

    <title>Gamepad</title>

    <link href='css/common.css' rel='stylesheet'></link>

    <!--The polyfill is not needed for browser that have native API support,
        but is linked by these samples for wider compatibility.-->
    <!--script src='https://cdn.jsdelivr.net/npm/webxr-polyfill@latest/build/webxr-polyfill.js'></script-->
    <script src='js/xrray-polyfill.js' type='module'></script>
    <script src='js/webxr-polyfill.js'></script>

    <script src='js/webxr-button.js'></script>
  </head>
  <body>
    <header>
      <details open>
        <summary>Gamepad</summary>
        <p>
          This sample demonstrates XRInputSource Gamepad integration. It shows 
          one box per available button. Pressing the button toggles the associated 
          box's color. Use joystick/touchpad input to move boxes in 2 dimensions.
          <a class="back" href="./index.html">Back</a>
        </p>
      </details>
    </header>
    <div id="gamepad-details">
      <!-- Tables updated in real-time data from WebXR gamepads will be
           displayed here if requested. -->
    </div>
    <script type="module">
      import {Scene} from './js/cottontail/src/scenes/scene.js';
      import {Renderer, createWebGLContext} from './js/cottontail/src/core/renderer.js';
      import {Gltf2Node} from './js/cottontail/src/nodes/gltf2.js';
      import {QueryArgs} from './js/cottontail/src/util/query-args.js';
      import {FallbackHelper} from './js/cottontail/src/util/fallback-helper.js';
      import {Node} from './js/cottontail/src/core/node.js';
      import {PbrMaterial} from './js/cottontail/src/materials/pbr.js';
      import {BoxBuilder} from './js/cottontail/src/geometry/box-builder.js';
      import {mat4, vec3, quat} from './js/cottontail/src/math/gl-matrix.js';
      import {GamepadTableManager} from './js/gamepad-data-tables.js';

      // If requested, initialize the WebXR polyfill
      if (QueryArgs.getBool('allowPolyfill', false)) {
        var polyfill = new WebXRPolyfill();
      }

      // If requested, don't display the frame rate info.
      let hideStats = QueryArgs.getBool('hideStats', false);

      // Display HTML tables updated in real-time with gamepad data. Useful for
      // testing + debugging.
      let displayTables = QueryArgs.getBool('displayTables', false);
      let tableManager = null;
      if (displayTables) {
        tableManager = new GamepadTableManager();
      }

      // XR globals.
      let xrButton = null;
      let xrRefSpace = null;

      // WebGL scene globals.
      let gl = null;
      let renderer = null;
      let scene = new Scene();
      if (hideStats) {
        scene.enableStats(false);
      }
      scene.addNode(new Gltf2Node({url: '../media/gltf/cube-room/cube-room.gltf'}));
      scene.standingStats(true);

      let floorSize = 10;
      let floorPosition = [0, -floorSize / 2 + 0.01, 0];
      let floorNode = null;

      let boxTable = {};

      class GamepadBox {
        constructor(position) {
          this.position = position;
          let boxBuilder = new BoxBuilder();
          boxBuilder.pushCube([0, 0, 0], 0.4);
          let boxPrimitive = boxBuilder.finishPrimitive(renderer);
          let boxMaterial = new PbrMaterial();
          boxMaterial.baseColorFactor.value = [1, 0, 0, 1]; // red
          this.renderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);

          this.node = new Node();
          this.node.addRenderPrimitive(this.renderPrimitive);
          scene.addNode(this.node);

          this.color_state = true;
          this.is_button_pressed = false;
        }

        toggle_color() {
          this.renderPrimitive.uniforms.baseColorFactor.value = this.color_state ?
              [0, 1, 0, 1] : // green
              [1, 0, 0, 1];  // red
          this.color_state = !this.color_state;
        }

        // If this was something like a full-fledged game instead of just a
        // sample, timestamps should be used when calculating how much to move
        // on each frame. The way this code is right now, having a higher frame
        // rate means the boxes move faster.
        move(dx, dy) {
          const inv_speed = 100;
          let translation = [dx / inv_speed, dy / inv_speed, 0];
          vec3.add(this.position, this.position, translation);
        }

        // Returns true iff button which was previously pressed is not pressed
        // anymore. The WebXR + Gamepad APIs don't support button press events
        // (yet) which is why keeping track of the state this way is necessary.
        update_button_state(is_button_pressed) {
          let did_button_fire = this.is_button_pressed && !is_button_pressed;
          this.is_button_pressed = is_button_pressed;
          return did_button_fire;
        }
      }

      class GamepadBoxSet {
        constructor(button_count, y) {
          // Place the boxes in a horizontal line 2 meters in front of the user.
          this.boxes = [];
          let x_shift = button_count / 2;
          for (let x = 1; x <= button_count; ++x) {
            this.boxes.push(new GamepadBox([x - x_shift, y, -2]));
          }
        }

        update_state(gamepad) {
          // A button press (pressing and then releasing a button) will change
          // the associated box's color from red to green (or from green to red
          // if it's currently green).
          for (let i = 0; i < gamepad.buttons.length; ++i) {
            if (this.boxes[i].update_button_state(gamepad.buttons[i].pressed)) {
              this.boxes[i].toggle_color();
            }
          }

          if (gamepad.mapping == "xr-standard") {
            if (gamepad.buttons.length >= 3 && gamepad.axes.length >= 2) {
              // Handle touchpad movement.
              // Invert the y axis because gamepads follow the convention that -1
              // is up/forwards, but we want to have a forward joystick/touchpad
              // input result in forward motion for the box.
              let dx = gamepad.axes[0];
              let dy = -gamepad.axes[1];
              this.boxes[2].move(dx, dy);
            }

            if (gamepad.buttons.length >= 4 && gamepad.axes.length >= 4) {
              // Handle thumbstick movement.
              let dx = gamepad.axes[2];
              let dy = -gamepad.axes[3];
              this.boxes[3].move(dx, dy);
            }
          }
        }

        update() {
          // Update the matrix for each box so that they are rendered in the
          // correct positions.
          for (let box of this.boxes) {
            mat4.identity(box.node.matrix);
            mat4.translate(box.node.matrix, box.node.matrix, box.position);
          }
        }
      }

      function ProcessInputSource(input_source) {
        if (displayTables) {
          tableManager.update(input_source);
        }

        let hand = input_source.handedness;
        let gamepad = input_source.gamepad;
        if (!(hand in boxTable)) {
          const y_positions = {
            "left" : 1,
            "right" : 2,
            "none" : 3,
          };
          boxTable[hand] = new GamepadBoxSet(gamepad.buttons.length, y_positions[hand]);
        }

        boxTable[hand].update_state(gamepad);
      }

      // Don't bother starting an inline session in this sample since WebXR
      // gamepads are not available during inline sessions.
      function initXR() {
        xrButton = new XRDeviceButton({
          onRequestSession: onRequestSession,
          onEndSession: (session) => session.end(),
          supportedSessionTypes: ['immersive-vr']
        });
        xrButton.addToHeader();
      }

      function initGL() {
        if (gl)
          return;

        gl = createWebGLContext({
          xrCompatible: true
        });
        document.body.appendChild(gl.canvas);

        function onResize() {
          gl.canvas.width = (gl.canvas.offsetWidth * window.devicePixelRatio);
          gl.canvas.height = (gl.canvas.offsetHeight * window.devicePixelRatio);
        }
        window.addEventListener('resize', onResize);
        onResize();

        renderer = new Renderer(gl);

        scene.setRenderer(renderer);
        scene.inputRenderer.setControllerMesh(new Gltf2Node({url: '../media/gltf/controller/controller.gltf'}));

        addFloorBox();
      }

      function addFloorBox() {
        let boxBuilder = new BoxBuilder();
        boxBuilder.pushCube([0, 0, 0], floorSize);
        let boxPrimitive = boxBuilder.finishPrimitive(renderer);

        let boxMaterial = new PbrMaterial();
        boxMaterial.baseColorFactor.value = [0.3, 0.3, 0.3, 1.0];
        let boxRenderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);

        floorNode = new Node();
        floorNode.addRenderPrimitive(boxRenderPrimitive);
        floorNode.selectable = true;
        scene.addNode(floorNode);
        mat4.identity(floorNode.matrix);
        mat4.translate(floorNode.matrix, floorNode.matrix, floorPosition);
      }

      function onRequestSession() {
        navigator.xr.requestSession('immersive-vr', {requiredFeatures: ['local-floor']}).then((session) => {
          xrButton.setSession(session);
          onSessionStarted(session);
        });
      }

      function onSessionStarted(session) {
        session.addEventListener('end', () => xrButton.setSession(null));

        initGL();

        session.updateRenderState({
          baseLayer : new XRWebGLLayer(session, gl)
        });

        session.requestReferenceSpace('local-floor').then((refSpace) => {
          // Save the session-specific reference space.
          xrRefSpace = refSpace;
          session.requestAnimationFrame(onXRFrame);
        });
      }

      function onXRFrame(time, frame) {
        let session = frame.session;
        let pose = frame.getViewerPose(xrRefSpace);
        scene.startFrame();
        session.requestAnimationFrame(onXRFrame);

        // Check for and respond to any gamepad state changes.
        for (let source of session.inputSources) {
          if (source.gamepad) {
            ProcessInputSource(source);
          }
        }

        if (displayTables) {
          tableManager.nextFrame();
        }

        for (let hand in boxTable) {
          boxTable[hand].update();
        }

        scene.updateInputSources(frame, xrRefSpace);
        scene.drawXRFrame(frame, pose);
        scene.endFrame();
      }

      // Start the XR application.
      initXR();
    </script>
  </body>
</html>
